John Cale's song "Let All Mortal Flesh Keep Silence" is a rendition of a hymn with the same name, which is based on a 4th-century Greek Christian liturgical chant called the Cherubic Hymn. The lyrics of the song focus on the profound awe and reverence that should be felt in the presence of Christ. The opening line, "Let all mortal flesh keep silence," sets the tone for the song, calling for all beings on earth to be still and in a state of reverence and fear. It suggests that human minds should not be focused on worldly matters but instead directed towards the divine. The lyrics go on to describe Christ's descent on earth, being born of Mary and yet being the King of kings and Lord of lords. This paradox highlights the divine nature of Christ and the humility with which he came into the world. The hymn also alludes to the Eucharist, a central Christian sacrament where believers partake of bread and wine as symbols of Christ's body and blood. The lyrics reflect on how Christ will give himself to the faithful as heavenly food, emphasizing the spiritual nourishment offered through communion with Christ. The imagery of the host of heaven, the angelic beings, descending alongside Christ adds to the sense of grandeur and glory. The powers of hell are depicted as vanishing in the presence of Christ's divine light, signifying his triumph over darkness and evil. The song concludes by referencing the seraphim, a specific order of angelic beings described in the Bible. The seraphim cover their faces in the presence of God, acknowledging his holiness, and continuously proclaim "Alleluia" in praise of the Lord most high. Overall, the song conveys a sense of reverence, awe, and the recognition of Christ's divinity and redemptive power. It encourages listeners to embrace a humble and reverent attitude in the presence of the divine.